1. Field
The present disclosure relates to a method and device for transmitting a reference signal in a communication system, and more particularly, to a method and device for transmitting a reference signal using uniform power boosting in a mobile system that uses a plurality of array antennas.
2. Description of Related Art
In order to meet wireless data traffic demands that have increased after the commercialization of the 4th Generation (4G) communication system, efforts to develop an improved 5G communication system or a pre-5G communication system have been made. For this reason, the 5G communication system or the pre-5G communication system is called a beyond-4G-network communication system or a post-LTE system.
In order to achieve a high data transmission rate, implementation of the 5G communication system on a super-high frequency (mmWave) band (e.g., 60 GHz band) is being considered. Beamforming, massive Multi-Input Multi-Output (MIMO), Full Dimensional MIMO (FD-MIMO), array antenna, analog beam-forming, and large-scale antenna technologies are being discussed to mitigate propagation path loss in the super-high frequency band and to increase propagation transmission distance in the 5G communication system.
Further, the 5G communication system results in the development of technologies, such as an evolved small cell, an advanced small cell, a cloud Radio Access Network (RAN), an ultra-dense network, Device to Device communication (D2D), a wireless backhaul, a moving network, cooperative communication, Coordinated Multi-Points (CoMP), and received interference cancellation, so as to improve the system network.
In addition, the 5G system results in the development of Hybrid FSK and QAM Modulation (FQAM) and Sliding Window Superposition Coding (SWSC) which are Advanced Coding Modulation (ACM) schemes, and Filter Bank Multi Carrier (FBMC), Non Orthogonal Multiple Access (NOMA), and Sparse Code Multiple Access (SCMA) which are advanced access technologies.
Meanwhile, the Internet has evolved into an Internet of Things (IoT) network in which distributed elements, such as objects, exchange and process information from a human-oriented connection network in which humans generate and consume information. Internet of Everything (IoE) technology may be an example of a combination of IoT technology and big data processing technology via a connection with a cloud server or the like.
In order to implement the IoT, technical factors, such as sensing technology, wired/wireless communication, network infrastructure, service interface technology, and security technology are required, and, thus, technologies such as a sensor network, Machine to Machine (M2M) communication, Machine Type Communication (MTC), and the like for a connection between objects are recently being researched.
In an IoT environment, via collection and analysis of data generated in connected objects, an intelligent Internet Technology (IT) service to create new values for peoples' lives may be provided. The IoT may be applied to fields such as a smart home, a smart building, a smart city, a smart car or connected car, a smart grid, healthcare, smart home appliance, or a high-tech medical service, via the convergence of the conventional Information Technology (IT) and various industries.
Accordingly, various attempts to apply the 5G communication system to the IoT network have been made. For example, 5G communication technologies such as a sensor network, M2M communication, MTC technology, and the like are implemented by the schemes such as beamforming, MIMO, array antenna, and the like. The application of a cloud RAN as the big data processing technology described above may be an example of convergence of the 5G technology and the IoT technology.
The current mobile communication system has been developed into a high-speed and high-quality wireless packet data communication system, so as to provide a huge-capacity data service and a multimedia service, beyond the voice-based service of the earlier era. In order to satisfy such demands, various standardization organizations such as 3GPP, IEEE, and the like, have standardized the 3rd generation evolved mobile communication system to which a multi-carrier based multiple access scheme is applied. Therefore, various mobile communication standards such as Long Term Evolution Advanced (LTE-A) of 3GPP, 802.16m of IEEE, and the like, have been developed based on the multi-carrier multiple access scheme, so as to support the high-speed and high-quality wireless packet data transmission service.
The currently existing 4th evolved mobile communication system, such as, LTE-A, 802.16m, and the like, is based on the multi-carrier multi-access scheme. To improve transmission efficiency, the system uses various technologies, such as, Multiple Input Multiple Output (MIMO, multiple antennas), beam-forming, Adaptive Modulation and Coding (AMC), channel sensitive scheduling, and the like. The above-described various technologies may use a method that concentrates transmission power transmitted from various antennas, controls the amount of data to be transmitted, selectively transmits data to a user who has a good channel quality, and the like, using various types of Channel Status Indications (CSIs), whereby the transmission efficiency may be improved and the system throughput may be increased.
Most of those schemes are operated based on channel status information of a channel between an evolved NodeB (eNB) (or Base Station (BS)) and a User Equipment (UE) (or a Mobile Station (MS)) and, thus, the eNB or the UE may need to measure a channel status between the eNB and the UE. In this instance, a Channel Status Indication Reference Signal (CSI-RS) is used. The above-described eNB is a downlink transmitter and uplink receiver located in a predetermined place. A single eNB may execute transmission and reception with respect to a plurality of cells. In a single mobile communication system, a plurality of eNBs are geographically distributed and each eNB may perform transmission and reception with respect to a plurality of cells.
The existing 3G and 4G mobile communication systems, such as, LTE, LTE-A, or the like, utilize the MIMO technology that executes transmission using a plurality of transmitting and receiving antennas to increase the data transmission rate and the system throughput. The MIMO technology performs transmission in a manner that spatially separates a plurality of information streams using a plurality of transmission/reception antennas. The transmission by spatially dividing the plurality of information streams is referred to as spatial multiplexing. Generally, the number of information streams to which spatial multiplexing is applicable may be defined as a rank of a corresponding transmission, and the rank may vary based on the number of antennas of a transmitter and a receiver. In the case of the MIMO technology supported in the standards up to LTE/LTE-A Release 12, spatial multiplexing for the cases in which the number of transmission/reception antennas are 2, 4, and 8, respectively, are supported, and a rank is supported up to 8.
There is a desire for a scheme of accurately measuring a channel between an eNB and a UE when the MIMO technology that performs transmission using a plurality of transmission/reception antennas is used as described above.
The above information is presented as background information only to assist with an understanding of the present disclosure. No determination has been made, as to whether any of the above might be applicable as prior art with regard to the present disclosure.